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Volume 129, Issue 2
Displaying 1-18 of 18 articles from this issue
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Paper
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Anton Lebedev, Dipali Thakkar, Dick Laro, Elena Lomonova, André ...2009 Volume 129 Issue 2 Pages 119-123
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSThis paper describes ways to overcome the major applicability limitations of a novel linear electromechanical actuator. Guidelines for selecting a proper soft magnetic material for a magnetic system of the actuator are presented. Conventional laminated electric steel and a soft magnetic composite material are compared based on the measured dynamic performance (up to 1000Hz) and manufacturability. A serious cross-coupling between two actuation directions of the actuator is identified and investigated. Improvements to the design are described. Experimental verification of the improved design is carried out by the two scientific groups. First measurement results show a significant (3 to 9 times) reduction of the cross-coupling.View full abstractDownload PDF (1101K) -
Shoji Satou, Keisuke Fujisaki2009 Volume 129 Issue 2 Pages 124-129
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSIn the continuous casting process, surface quality of steel is as important as its productivity. The surface quality is mostly decided in the molten metal flow during initial solidification stage, which progresses at the free surface of the molten steel. To improve the surface quality, this flow must be controlled. M-EMS generates the time-varying electromagnetic force, which helps to control the shape of the free surface. In this paper, we evaluate the possibility of controlling the flow at the free surface by the MHD calculations. The result showed a little possibility of the flow at the free surface being controlled. Though the free surface variation in a pulsed EMC process, which controls the shape of the free surface using the time-varying electromagnetic force component, depends on electromagnetic force, the time-varying component in the M-EMS is decided by the velocity of the molten metal. Since there is a first-order lag between the electromagnetic force and this velocity, free surface variation in M-EMS does not linearly depend on the time-varying electromagnetic component.View full abstractDownload PDF (837K) -
Tsutomu Kominami, Yasutaka Fujimoto2009 Volume 129 Issue 2 Pages 130-135
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSLinear actuators are used in various industrial applications. Connentional linear actuators are a combination of a rotational motor and a ball screw, a hydraulic actuator, or a linear motor. However, these actuators have some demerits. This paper proposes a spiral motor (SPRM) that comprises a spiral stator and a spiral mover. Owing to its spiral structure, the SPRM can be expected to show better performance as compared to the conventional linear actuator. However, it is not easy to manufacture spiral stators and spiral movers. In this paper, thrust and torque equations derived from a magnetic circuit are introduced. A prototype is developed and its specifications are provided. Sixty fan-shaped stator blocks are mounted on the frame and forty-eight fan-shaped mover blocks with flat surfaces are mounted on the axis. These blocks form an approximately spiral structure. The blocks are not difficult to manufacture. The feasibility of the developed SPRM is confirmed by performing basic experiments. First, the SPRM is driven by using synchronous control. Subsequently, the thrust is measured by a load cell and the thrust constant is determined.View full abstractDownload PDF (1899K) -
Yuki Yokokura, Seiichiro Katsura, Kiyoshi Ohishi2009 Volume 129 Issue 2 Pages 136-143
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSIn the real world, robots should be able to recognize the environment in order to be of help to humans. A video camera and a laser range finder are devices that can help robots recognize the environment. However, these devices cannot obtain tactile information from environments. Future human-assisting-robots should have the ability to recognize haptic signals, and a disturbance observer can possibly be used to provide the robot with this ability. In this study, a disturbance observer is employed in a mobile robot to functionalize the tactile sensation.
This paper proposes a method that involves the use of haptograph and modal decomposition for the haptic recognition of road environments. The haptograph presents a graphic view of the tactile information. It is possible to classify road conditions intuitively. The robot controller is designed by considering the decoupled modal coordinate system, which consists of translational and rotational modes. Modal decomposition is performed by using a quarry matrix. Once the robot is provided with the ability to recognize tactile sensations, its usefulness to humans will increase.View full abstractDownload PDF (1387K) -
Tatsuya Okuda, Takahiro Urakabe, Yoshikazu Tsunoda, Toshiyuki Kikunaga ...2009 Volume 129 Issue 2 Pages 144-149
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSA novel technique for reducing the ripple current in a DC link capacitor by harmonic control of the DC/DC converter and PWM inverter is proposed in this paper. The proposed technique synchronizes the switching frequencies of the PWM inverter and the DC/DC converter and optimizes the phase difference of the carrier waveforms between them. The effectiveness of our technique is shown by simulation and an experiment conducted with a 10-kW PM motor drive system. In comparison to the conventional technique, the proposed technique reduces the ripple current in the DC link capacitor by 20-40% in a PWM inverter drive system with a DC/DC converter.View full abstractDownload PDF (916K) -
Shigeru Susa, Tomoyuki Shimono, Kouhei Ohnishi2009 Volume 129 Issue 2 Pages 150-157
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSIn micro-macro bilateral control systems, it is important to use position and force scaling factors that depend on the size of the master and slave system. Moreover, it is vital for control systems to use appropriate control gains depending on the scaling ratio between master and slave response. This paper proposes a micro-macro bilateral control system based on the scaling of control gains. In this system, the control gains of the master and slave system are adjusted to appropriate values by using control gain scaling factors. These scaling factors are obtained by designing a micro-macro bilateral control system to achieve ideal reproducibility. To verify the validity of the proposed system, analytical results for the reproducibility, operationality, and stability of the proposed control system are presented in this paper. Moreover, the proposed system is used in an experimental micro-macro bilateral system, and the results are presented.View full abstractDownload PDF (1485K) -
—Intended for Use in High-Performance Controller—Yuichiro Nozaki, Takafumi Koseki2009 Volume 129 Issue 2 Pages 158-165
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSA linear induction motor (LIM) is suitable for use in trains; the motor can be used in both wheel-suspended and contact-less types such as Linear Metro and HSST trains in Japan. The LIM has the end winding as well as asymmetrical winding. The end-effect is a major problem in the LIM, and it makes the analysis, design, and control of motors difficult. In this paper, the combination method of numerical analysis and equivalent circuit of the LIM is described in order to design a high-performance controller of the LIM includeing the end effect. A sample basic field-oriented control scheme that is based on the plant model is applied to the LIM in order to check the control performance; the theory of rotary induction motor is used for the verification.View full abstractDownload PDF (1022K) -
Tsubasa Shioya, Yasutaka Fujimoto2009 Volume 129 Issue 2 Pages 166-172
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSIn this paper, we introduce a simulator for ice thermal storage systems. Basically, the refrigeration system is modeled as a linear discrete-time system. For system identifications, the least square method is used. However, it is difficult to identify the switching time of the electromagnetic valve of brine pipes attached at showcases accurately by this method. In order to overcome this difficulty, a simulator based on the stochastic switched ARX model is developed. The data obtained from the simulator are compared with actual data. We verify the effectiveness of the proposed simulator.View full abstractDownload PDF (672K) -
Takahiro Hoshino, Kazuhiro Tsuboi, Kazuo Yamanaka, Yoshio Hamamatsu2009 Volume 129 Issue 2 Pages 173-183
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSIt is important to discuss the behavior of traffic at merging sections for the design and realization of an automated guided vehicle system (AGVS). In this study, we deal with a merging section of the AGVS by considering a time limit for the merging of vehicles. Near the merging section, traffic flowing in one direction must form a queue to avoid collisions between vehicles. We propose an improvement in the control strategy proposed in the previous research. However, it is difficult to analyze the mathematical model of the merging section. Analysis can be performed only for the case in which the time limit is one unit. We also propose a method for analyzing the model for an arbitrary time limit using a linear recurrence relation. We quantitatively discuss the influence of the time limit on the average queue length and the detour rate.View full abstractDownload PDF (617K) -
Bu Yinggang, Ryota Aotsuka, Tsutomu Mizuno2009 Volume 129 Issue 2 Pages 184-190
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSLinear oscillatory actuators (LOAs) are widely used in linear-motor shavers, electric toothbrushes and mobile phone vibrators as high-speed oscillatory driving devices. The maximum amplitude of the mover is obtained at a resonance frequency that is determined from the spring constant and the mass of the mover. However there is a problem with these actuators: the amplitude decreases sharply when the driving frequency differs from the resonance frequency in a mechanical vibration system with small damping. In this paper we propose a control of resonance frequency in which the thrust, which shows the characteristics of a spring, is generated based on the displacement of the mover and damping factor in which the thrust, which shows the characteristics of a damping, is generated based on the velocity of the mover. The proposed method ensures that the resonance frequency always corresponds to the driving frequency and that rapid changes in the amplitude are avoided.View full abstractDownload PDF (1198K) -
Shinji Shinnaka2009 Volume 129 Issue 2 Pages 191-200
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSThe phase, frequency, and amplitude of single-phase voltages are the most important and basic information required for single-phase grid connected applications. This paper proposes a new “D-estimation method” for instantly and adaptively estimating the phase, frequency, and amplitude of frequency-varying single-phase signals in such applications. The D-estimation method has the following attractive features: 1) it is a new filtering method using the D-filters; 2) it involves the use of only filters and can be easily designed; 3) even in hostile envelopments caused by a frequency variation, a phase jump, amplitude sag/swell, harmonic distortion, and/or contaminated noise, good instant estimates of the phase, frequency, and amplitude can be obtained; 4) it is simple, but can exhibit high performance similar to the “robust PLL method”. This paper presents the D-estimation method together with the design rules in detail; the usefulness of the method is verified by performing extensive numerical experiments.View full abstractDownload PDF (2004K) -
Hiroyuki Miyamoto, Masayuki Morimoto, Katsuaki Morita2009 Volume 129 Issue 2 Pages 201-206
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSBattery driven tramcars (wireless tramcars) have reached the actual application stage. The most important factor to be considered during the operation of the tramcar is the state of charge (SOC) of the battery. The purpose of this study is to develop on-line method for SOC estimation; the method employs an equivalent circuit of a battery. SOC estimation using a conventional equivalent circuit results in a large error during fast current transients. In order to improve the accuracy of the estimation, we propose the use of a equivalent circuit of a Li-ion battery. Experimental results show that the accuracy of SOC estimation is better when the proposed circuit is used as compared to the accuracy when a conventional equivalent circuit is employed. However, the proposed equivalent circuit results in an error when the temperature of the battery varies. Therefore, we propose a new method for SOC estimation in which the temperature is taken into consideration. This method requires only the measurement of the voltage and current, and therefore, temperature measurement is not required. Experimental results show that the accuracy of the proposed method is greatly improved with the temperature is taken into consideration. The proposed method can be applied to actual wireless tramcar.View full abstractDownload PDF (476K) -
Tetsuya Sugio, Masayoshi Yamamoto, Shigeyuki Funabiki2009 Volume 129 Issue 2 Pages 207-213
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSThe use of an SMES (Superconducting Magnetic Energy Storage) for smoothing power fluctuations in a railway substation has been discussed. This paper proposes a smoothing control method based on fuzzy reasoning for reducing the SMES capacity at substations along high-speed railways. The proposed smoothing control method comprises three countermeasures for reduction of the SMES capacity. The first countermeasure involves modification of rule 1 for smoothing out the fluctuating electric power to its average value. The other countermeasures involve the modification of the central value of the stored energy control in the SMES and revision of the membership function in rule 2 for reduction of the SMES capacity. The SMES capacity in the proposed smoothing control method is reduced by 49.5% when compared to that in the nonrevised control method. It is confirmed by computer simulations that the proposed control method is suitable for smoothing out power fluctuations in substations along high-speed railways and for reducing the SMES capacity.View full abstractDownload PDF (1127K) -
Atsushi Kobayashi, Nadia Mei Lin Tan, Shigenori Inoue, Hirofumi Akagi2009 Volume 129 Issue 2 Pages 214-221
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSThis paper describes the design, construction, and testing of a 320-V, 12-F EDLC energy storage bank equipped with a bidirectional isolated dc-dc converter. A simple voltage-balancing circuit is proposed, which combines a center-tapped high-frequency transformer and the EDLC bank consisting of two 160-V, 24-F EDLC sub-banks connected in series. Experimental results including charging/discharging and self-starting waveforms are shown to verify the effectiveness of the proposed voltage-balancing circuit. The power loss in the voltage-balancing circuit is verified to be negligibly small during the charging/discharging operation.View full abstractDownload PDF (774K) -
—Experiments Using Elderly Driver—Naohisa Hashimoto, Shin Kato, Sadayuki Tsugawa2009 Volume 129 Issue 2 Pages 222-227
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSWe studied different types of guidance systems and proposed some comprehensive human machine interfaces (HMIs) using this system for providing instructions for vehicle control to elderly drivers. Experimental studies and a questionnaire survey were carried out for evaluating the validity of the system. HMI was evaluated on the basis of experiments involving eighteen elderly drivers. All the drivers could steer their respective vehicles to the target parking space without swerving. Thus, the proposed HMI was confirmed to be useful instructions to elderly drivers in this road-side parking assistance system.View full abstractDownload PDF (1175K)
Letter
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Noboru Katayama, Hideyuki Kamiyama, Yusuke Kudo, Sumio Kogoshi, Takafu ...2009 Volume 129 Issue 2 Pages 228-229
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSThe payback period of a fuel cell auxiliary power unit for a large track was discussed under the present conditions in Japan. However, the calculation is complex since the calculation includes various parameters and iteration. In the present study, the approximation of the payback period has been proposed and compared with the exact solution. The results have shown the both are in good agreement.View full abstractDownload PDF (234K) -
Hirokazu Matsumoto2009 Volume 129 Issue 2 Pages 230-231
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSThis paper proposes a boost motor driver with EDLC as a new boost motor driver. The boost motor driver has two advantages against conventional boost motor drivers. The first is that the boost motor driver can decrease an input power peak. The second is that the boost motor driver can charge almost all regeneration energy. The dynamic performance of boost voltage and these advantages of the boost motor driver is simulated. From the simulation, results that the boost motor driver has good performance are derived.View full abstractDownload PDF (478K) -
Bin Liu, Tsuginori Inaba2009 Volume 129 Issue 2 Pages 232-233
Published: February 01, 2009
Released on J-STAGE: February 01, 2009
JOURNAL FREE ACCESSFor this study, the dynamic reduction effect of CO2 gas discharge for change from internal combustion engines to electric vehicles, EVs, was investigated quantitatively. The Japanese power generation status, which shows characteristics of electricity generation, and optimized adjustment to electricity demand, load and environment was examined. Based on a CO2 gas discharge basic unit, the estimated reduction quantity of CO2 gas discharge from EVs was calculated. The reduction effect of CO2 gas discharge is expected to be 52% by changing gas-fuelled vehicles to EVs. However, the dynamic differential is only 19% reduction by using the thermal power and -2% if only the coal thermal power is used.View full abstractDownload PDF (272K)
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